Mousepad is part of Xfce which is in the repository. If you want this editor stand-alone (without Xfce) what you are really looking for is leafpad. There is a leafpad package in the VL 6.0 repository that wll probably work fine with 5.9 as well. I did plan on building a leafpad package for 5.9 and I will get to it as soon as I can.